1. Technical Field
Aspects of this document relate generally to traffic preemption systems.
2. Background Art
Traffic preemption systems are conventionally used to permit emergency and other vehicles to change a traffic light initially red at an intersection to green prior to their arrival. With the light in the vehicle's favor, the vehicle does not need to wait or to drive on the wrong side of the street to avoid stopped vehicles at the light. In addition, conventional traffic preemption systems have been used to aid public transportation vehicles, such as buses, to maintain headway relative to other vehicles during high traffic periods.
Currently, such systems rely on optical or infrared emitters within the vehicle preemption unit of the system to emit a signal that is detected by the systems detection unit, thereby leading to a change in a traffic signal based on the optical or infrared signal detected. Current infrared systems require sizeable emitting optics due to the source size to control the divergence of an infrared signal so that an appropriate beam width can be achieved for proper detection.